preservation of Holland from the like inundation, the level of the Fenn is become four feet higher than the level of Marshland, as Mr Vermuiden assured me upon a view and observation thereof.”—Afterward he observes, “That the time when the passage of Wisbeach was so silted up, as that the outfall of the great river Ouse, which was there, became altered, and was diverted to Lynn, was in Henry the third’s reign, as my testimonies (says he) from records manifest.” In his 5th Letter he says to his friend—“Since I wrote to you for your opinion touching the various course of the sea, I met with some notable instances of that kind in a late author, viz. _Olivarius Uredius_, in his History of Flanders; which he manifesteth to be occasioned from _Earthquakes_.”—And this appears to have become afterward our author’s own settled opinion, as to the ancient influx of the sea over this great level country. SECTION V. _A concise view of the ancient and modern history of the Fen Country_, _from Pennant’s Preface to his third volume of Arctic Zoology_. Among the modern authors who have treated of these Fens, no one, perhaps, ranks higher than Pennant. Of this singular tract of country he gives the following account. “The great Level, which comprehends Holland in this county, [Lincolnshire] with part of Northamptonshire, Huntingdonshire, Cambridgeshire, Suffolk and Norfolk, a tract of sixty computed miles in length, and forty in breadth, had been originally a wooded country. Whole forests of firs and oaks have been found in digging, far beneath the moor on the solid ground; oaks fifteen feet in girth, and ten yards long, mostly burnt at the bottoms, the ancient method of falling them: multitudes of others entirely rooted up, as appears, by the force of the sea bursting in and overwhelming this whole tract, and covering it with silt, or mud which it carried with it from time to time. “In process of time, this tract underwent another revolution. The silt or mud gained so considerably as to leave vast spaces dry, and other parts so shallow, as to encourage the Romans to gain these fertilised countries from the sea. Those sensible and indefatigable people first taught us the art of embanking, and recovered the valuable lands we now possess. It was the complaint of _Galgacus_, that they exhausted the strength of the Britons, _in sylvis et paludibus emuniendis_, {53a} in clearing woods and draining marshes.